Bookmarks bar, folders & list positioning

Hi all, Apologies if this has been posted already - I had a quick search through the site but couldn't find anything definitive. I was wondering if there was a fix/workaround, or if there is a known issue for the position of a bookmark dropdown list from a folder on the bookmark bar when the UI is zoomed? To explain - at 100% UI zoom, if I click on a folder on my bookmark bar, a dropdown list of bookmarked sites/pages appears below & in line with the clicked folder. If I zoom the UI out to 80%, and perform the same action, the dropdown displays in the same position it would as if the UI was at 100%.